803
FXUS63 KFSD 101723
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1223 PM CDT MON MAR 10 2025
KEY MESSAGES
- AN EXTENDED PERIOD OF SEASONALLY WARM TEMPERATURES CONTINUES
THROUGH MUCH OF THE UPCOMING WEEK. HIGHS ARE LIKELY TO PUSH
RECORD VALUES MONDAY AND AGAIN TOWARDS THE END OF THE WEEK.
- ELEVATED TO CRITICAL FIRE DANGER IS LIKELY MONDAY NORTH OF
I-90, AND ALONG THE HIGHWAY 14 CORRIDOR. FIRE DANGER RETURNS
AGAIN THURSDAY.
- A STRONG SPRING STORM STILL ON TRACK FOR THE END OF THE WEEK
AND START OF NEXT WEEKEND. THIS STORM MAY BRING ALL ASPECTS OF
SPRING WEATHER TO THE REGION INCLUDING THUNDERSTORMS, HIGH
WINDS, AND EVEN SNOW.
- NEAR 100% PROBABILITIES OF PRECIPITATION WITH THIS SYSTEM,
WITH OVER 70% PROBABILITIES OF MEASURABLE SNOW BY SATURDAY.
WITH EXPECTATIONS OF STRONG WINDS SATURDAY, START MONITORING
THIS SYSTEM.
UPDATE
ISSUED AT 1124 AM CDT MON MAR 10 2025
LATEST OBSERVATIONAL TRENDS HAVE BEEN ON TRACK THROUGH THE MORNING
HOURS. THE EARLY MORNING CIRRUS CONTINUES TO PUSH EAST OF THE AREA
LATE THIS MORNING WHILE MINIMAL CIRRUS IS EXPECTED FOR THE AFTERNOON
HOURS. 12Z SOUNDINGS SHOW LOCATIONS IN SOUTHWEST MINNESOTA AND SOUTH
CENTRAL SOUTH DAKOTA MIXING DOWN GUSTS AT OR SLIGHTLY ABOVE 25 MPH
WITH RELATIVE HUMIDITY VALUES FALLING SQUARELY BELOW 25%. AM
EXPECTING THIS TO OCCUR DUE TO EFFICIENT MIXING BEING REACHED. THUS,
CONFIDENCE HAS INCREASED IN RED FLAG CONDITIONS BEING MET IN
ADDITIONAL PARTS OF SOUTH CENTRAL SOUTH DAKOTA AND SOUTHWEST
MINNESOTA. AS SUCH, HAVE EXPANDED THE RED FLAG WARNING TO INCLUDE
THESE AREAS. HOWEVER, HAVE DECIDED TO LEAVE GREGORY COUNTY OUT OF
THE WARNING DUE TO REMAINING SNOWPACK ACROSS THE COUNTY.
DISCUSSION
ISSUED AT 245 AM CDT MON MAR 10 2025
THIS MORNING: CIRRUS CONTINUES TO SPILL THROUGH THE NORTHERN PLAINS
THIS MORNING, PREVENTING ANY SIGNIFICANT FALL IN OVERNIGHT LOW
TEMPERATURES AND SETTING THE STAGE FOR A VERY WARM DAY ON MONDAY.
MONDAY: THANKS TO A BREEZY AND DRY WESTERLY WIND THROUGH THE DAY,
TEMPERATURES ARE EXPECTED TO CLIMB WELL INTO THE 60S IN MOST
LOCATIONS, AND PERHAPS INTO THE 70S ALONG PORTIONS OF THE JAMES
RIVER VALLEY. BIGGEST QUESTIONS TODAY REVOLVE AROUND LINGERING
IMPACTS OF COLD/WET GROUND FROM RECENT SNOW COVER, AND THEN DEPTH OF
MIXING LATER THIS AFTERNOON. IF WE CAN BEGIN TAPPING INTO THE
800:700 MB LAYER, THEN SOME GUSTY AFTERNOON WINDS TOWARDS THE 20 TO
25 KNOT RANGE ARE POSSIBLE, HIGHEST ALONG THE HIGHWAY 14 CORRIDOR.
THE DEEPER WE MIX, THE LOWER DEW POINTS WILL ALSO DROP, AND HAVE
TRENDED TOWARDS THE RAP/HRRR BLENDS. THE END RESULT WILL BE ELEVATED
TO CRITICAL FIRE DANGER WHICH WILL BE EXPANDED ON FURTHER IN THE
FIRE WEATHER DISCUSSION.
TONIGHT: A MODEST PUSH OF LOW-LVL COLD AIR ADVECTION WILL SINK
SOUTHEAST THROUGH THE AREA DURING THE EVENING AND EARLY
OVERNIGHT HOURS. MODEL GUIDANCE HAS BACKED OFF HIGH WINDS
SLIGHTLY, BUT LOOKING AT SOUNDINGS, STILL NOTICING A BRIEF
WINDOW FOR 30+ KNOT GUSTS.
TUESDAY-THURSDAY: SURFACE HIGH PRESSURE TRACKS THROUGH THE WESTERN
GREAT LAKES DURING THE DAY ON TUESDAY, ALLOWING WINDS TO SHIFT
THROUGHOUT THE DAYTIME HOURS IN THE TRI-STATE REGION. WE'LL SEE
SLIGHTLY LOW-LVL WARM ADVECTION BEGIN EARLY ON TUESDAY WITH HIGHS
CLIMBING INTO THE LOWER TO MIDDLE 40S. WARMER AIR IN THE 925:850 MB
LAYER STREAMS NORTHWARD OVERNIGHT WITH LOW TEMPERATURES STAYING
FAIRLY WARM INTO WEDNESDAY MORNING. DESPITE THE LIGHT NORTHERLY
WINDS AND VERY WEAK COLD AIR ADVECTION, WE SHOULD STILL SEE HIGH
TEMPERATURES RISE INTO THE 60S UNDER A MOSTLY SUNNY SKY. IN
RESPONSE TO A DEEP UPPER TROUGH MOVING TOWARDS THE FOUR CORNERS
REGION THURSDAY MORNING, SOUTHERLY LOW-LVL AND BOUNDARY LAYER WINDS
WILL DEVELOP IN EARNEST THROUGH THE DAY ON THURSDAY. THE PASSAGE OF
AN EARLY MORNING WARM FRONT IS EXPECTED TO USHER IN HIGH
TEMPERATURES NEARLY 25+ DEGREES ABOVE NORMAL AND TOWARDS THE 70
DEGREE MARK. GUSTY AFTERNOON WINDS MAY PUSH FIRE DANGER
UPWARDS, HOWEVER WE'LL ALSO LIKELY BEGIN TO SEE THE ADVECTION OF
UPPER 30 TO 40 DEWPOINTS INTO THE REGION. PERSISTENT SOUTHERLY
WINDS CONTINUE INTO FRIDAY MORNING, WITH AN INCREASED POTENTIAL
FOR RECORD WARM OVERNIGHT LOW TEMPERATURES.
FRIDAY-SUNDAY: THE BIG STORY OF THE UPCOMING WEEK CONTINUES TO BE
THE POTENTIAL FOR A CLIMATOLOGICALLY SIGNIFICANT SPRING STORM THAT
WILL MOVE THROUGH THE PLAINS AND INTO THE UPPER MIDWEST BY THE
LATTER HALF OF THE WEEKEND. MODEL GUIDANCE REMAINS FAIRLY CONSISTENT
5-6 DAYS OUT, BUT A DEEPER LOOK AT THE ENSEMBLES SUGGESTS TWO
DIFFERENT SCENARIOS DEVELOPING. CAMP 1 FEATURES MOST OF THE EC AND
CMC ENSEMBLE MEMBERS THAT INDICATES THE UPPER LOW TRACKS A BIT MORE
TO THE SOUTH OF THE GFS/GEFS TRACK BEFORE PIVOTING INTO SOUTHEAST
MINNESOTA. THE EC/CMC ARE ALSO A BIT SLOWER TO DEEPEN THE UPPER LOW
ACROSS IOWA. CAMP 2 FEATURES MOST OF THE GEFS MEMBERS IN WHICH THE
GFS IS A FAIRLY GOOD REPRESENTATION OF THE IDEA THAT THE WAVE WILL
BE DEEPER AND SLIGHTLY FURTHER NORTH AS IT MOVES OUT OF THE
OKLAHOMA PANHANDLE.
LET'S LOOK AT THE COMMONALITIES OF THESE SOLUTIONS THOUGH. BOTH
CAMPS INDICATE NEAR RECORD TEMPERATURES FRIDAY AND FRIDAY NIGHT.
BOTH SUGGEST STRONG MOISTURE ADVECTION NORTHWARD FRIDAY, WITH
INCREASING RISKS FOR SCATTERED CONVECTION MOVING INTO THE TRI-STATE
AREA FRIDAY AFTERNOON AND EVENING. IN FACT, MUCAPE LIFTED OFF AN
ELEVATED SURFACE (SINCE SOME SURFACE CAPPING IS POSSIBLE) SITS
AROUND 500 TO 800 J/KG. ANALOGS AND SOME AI BASED MODELS WOULD EVEN
SUGGEST A LOW SEVERE RISK IN THE EASTERN CWA. BOTH CAMPS OF
SOLUTIONS WOULD SUGGEST A TROWAL DEVELOPING ON THE WESTERN FLANK OF
THIS SYSTEM WITH RAIN CHANGING OVER TO MODEST ACCUMULATING SNOW AS
THE SYSTEM FILLS AND MOVES EAST. SHOULD COLDER AIR ALSO GET PULLED
INTO THIS SYSTEM FASTER, THEN SOME REFREEZE OR ICING IS POSSIBLE.
BOTH SOLUTIONS ALSO INDICATE HIGH PROBABILITIES (>60%) OF ADVISORY
LEVEL WINDS FOCUSED ALONG AND WEST OF I-29 SATURDAY.
THE DIFFERENCES HOWEVER ARE MORE IMPACTFUL. THE DEEPER AND FURTHER
NORTH GEFS/GFS SOLUTIONS DEVELOP A MUCH DEEPER TROWAL AND HENCE
WOULD PRODUCE SOME FAIRLY SIGNIFICANT SNOW/WIND IMPACTS WEST OF I-
29. CIPS ANALOGS OF THE GFS PULL UP SEVERAL VERY IMPACTFUL EARLY
SPRING BLIZZARDS FOR THE DAKOTAS.
GIVEN THE MODEL DIFFERENCES, THE NBM DATA SET REMAINS A BIT
WASHED OUT, THOUGH WITH A HIGHER NUMBER OF INPUTS FAVORING THE
EC/CMC SOLUTIONS, THERE IS SOME PREFERENCE THERE. THERE REMAINS
PLENTY OF TIME FOR THESE CAMPS COME TOGETHER, BUT THIS IS
CERTAINLY A STORM TO MONITOR ESPECIALLY IF YOU HAVE TRAVEL
PLANS THIS WEEKEND.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1221 PM CDT MON MAR 10 2025
VFR CONDITIONS ARE EXPECTED FOR THE TAF PERIOD. WESTERLY WINDS
REMAIN LIGHT EARLY THIS AFTERNOON. HOWEVER, AS MIXING INCREASES
THROUGH THE AFTERNOON HOURS, WINDS WILL STRENGTHEN. GUSTS UP TO 15
TO ABOUT 25 KNOTS IS EXPECTED FOR THE AFTERNOON HOURS, STRONGEST
NORTH OF I-90 AND WEST OF THE JAMES RIVER. WINDS WILL BRIEFLY WEAKEN
THIS EVENING BEFORE RESTRENGTHENING OVERNIGHT AS A COLD FRONT PUSHES
THROUGH THE AREA AND TURNS THE WIND DIRECTION TO OUT OF THE NORTH.
GUSTS UP TO 20-30 KNOTS IS EXPECTED FOR THE OVERNIGHT HOURS. WINDS
WILL WEAKEN THROUGH THE MORNING HOURS TOMORROW WHILE TURNING
EASTERLY TO FINISH OUT THE TAF PERIOD.
FIRE WEATHER
ISSUED AT 245 AM CDT MON MAR 10 2025
A VERY WARM AND DRY DAY IS ANTICIPATED FOR MONDAY. WITH INCREASING
WESTERLY AFTERNOON WINDS, WE'LL SEE TEMPERATURES INTO THE 60S AND
70S. SOUNDINGS SUGGEST WE'LL MIX AOA 800 MB, TAPPING INTO VERY DRY
AIR AND ALSO POTENTIAL FOR MID-AFTERNOON GUSTS UPWARDS OF 20 TO
25+ KNOTS. HAVE TRENDED MORE TOWARDS THE HRRR/RAP MODELS WITH
DEEPER OVERALL MIXING. RH LIKELY PLUMMETS AS LOW AS 18%. THIS
WOULD PLACE AREAS ALONG HIGHWAY 14 INTO CRITICAL FIRE DANGER
LEVELS FROM MID- AFTERNOON INTO EARLY EVENING. CRITICAL RH
EXPANDS OVER MUCH OF THE FORECAST AREA TODAY, BUT WINDS MAY END
UP BEING JUST BELOW CRITERIA TOWARDS I-90. PLUS, FUELS MAY STILL
BE RECOVERING FROM RECENT SNOW. WE'LL HAVE TO MONITOR
OBSERVATIONS CLOSELY TODAY, WITH POTENTIAL SOUTHERN EXPANSION
TOWARDS CHAMBERLAIN, MITCHELL, MADISON AND PIPESTONE, IF
STRONGER WINDS SPREAD FURTHER SOUTH.
THE NEXT FIRE WEATHER DAY MAY DEVELOP ON THURSDAY AS DEEP SOUTHERLY
FLOW DEVELOPS. POTENTIAL AGAIN FOR GUSTS WELL OVER RED FLAG
CRITERIA IN THE AFTERNOON WITH TEMPERATURES INTO THE 70S.
HOWEVER, HIGHER DEWPOINTS MAY BEGIN TO MOVE NORTHWARD KEEPING
RELATIVE HUMIDITY VALUES WELL ABOVE CRITICAL THRESHOLDS.
FSD WATCHES/WARNINGS/ADVISORIES
SD...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR SDZ038>040-
052>059-063-064.
MN...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR MNZ071-072-
080-081-097.
IA...NONE.
NE...NONE.
UPDATE...MEYERS
DISCUSSION...DUX
AVIATION...MEYERS
FIRE WEATHER...DUX
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